Printing and manufacturing equipment may employ micro-fluidic structures to route material to a surface or to form structures. For example, jet stacks used in printing typically consist of a stack of thin metal plates stacked together. Each plate has openings that mate with other openings in other plates to form channels, manifolds and other fluidic structures to route ink from one side of the jet stack to a nozzle plate. The nozzle plate has an array of apertures that allow the ink to selectively jet onto a surface.
Recently, some jet stacks have introduced polymer or other layers into the stack, either as adhesive layers or to replace one or more of the metal plates. These layers will also contain openings, typically made by a laser at some point in the manufacturing of the jet stack. In some instances, the opening to be etched in the polymer layer lies over a void or cavity in the stack below the layer. This may cause a piece of the area being ablated in the polymer to break off and fall into the cavity below. This may result in an unintended obstruction being left in the resulting structure, especially those in which the cavities form a micro-fluid channel such as jet stacks mentioned above. The piece, referred to here as a chad, may partially or completely block the passage ways through which fluid should flow. The clog causes failures in the printing and manufacturing equipment or faults in the resulting product. In some cases a second laser process can be used to etch layers that are opposite the first etched polymer layer and the cavity. In this case the chad may interfere with the second laser etching process. This issue may arise with materials other than polymers.